Horn blowing apparatus for motor vehicles



Sept. 9, 1952 F. M. STELLA 2,610,235

HORN BLOWING APPARATUS FOR MOTOR VEHICLES Filed March 11, 1949 4 Sheets-Sheet l I5 2 IN VEN TOR.

FRANK M. 51:144. BY

AI'TO R/VEX Sept. 9, 1952 F. M. STELLA HORN BLOWING APPARATUS FOR MOTOR VEHICLES Filed March 11, 1949 4 Sheets-Sheet 2 4 INVENTOR.

FRANK M- STELLA.

ATT R/vL-K Sept. 9, 1952 F. M. STELLA HORN BLOWING APPARATUS FOR MOTOR VEHICLES Filed March 11, 1949 4 Sheets-Sheet 3 INVENTOR.

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FRANK M STELLA. BY ,"L/ 7 7"" (I I f -r TO R N f Patented Sept. 9, 1952 HORN BLOWING APPARATUS FOR MOTOR VEHIGIJES Frank M. Stella, Detroit, Mich lassi norto Power. Brake Parts Manufacturing :Company, Detroit, Mich, a corporation of Michigan Application March 11, 1949, Serial No. 80,883

2 Claims. .1 i The present invention pertains to a novel horn blowing apparatus for :a motor vehicle, particularly motor trucks.

It is well known in the art that such vehicles require powerful horns which in many cases are operated by compressed air. Such installations require an air storage tank and a compressor to supply it. The compressor in some present installations is operated by the vacuum in the intake manifold. The suction-operated compressor has proved unsatisfactory under certain conditions, for example, when the engine is working under heavy load and there is little reduction of pressure in the-manifold.

One of the objects of this invention is to eliminate the objections of a suction-driven compressor and to provide a more positive and reliable drive. This object is accomplished generally by providing an electric motor for driving the compressor. An electric motorjhowever, raises problems of current supply and battery drainage. Another object of the invention in this connection is to provide an electrical system that avoids drainage of the battery and also gives the electric motor a higher amperage. In the accomplishment of the latter object, the circuit of the electric motor is governed by a normally open relay which must be closed in order to make current availableflto the motor. The energizing coil that closes the relay receives its current from theconventional generator of the vehicle. Consequently the relay is closed only when thegenerator is running, and the electric .motor cannot drain the battery. Further, with the generator in operation, the motor .reiceives a somewhat .higher voltage and a substantially higher amperage than can be delivered by the battery.

Another object of the invention is to control the motor circuit by the air pressure in the storage tank. In this connection the motor circuit includes a snap action switch that is opened when a predetermined pressure is attained in the tank. In one embodiment of the invention it is desired to reduce the pressure in the compressor when the electric motor is stopped, in order to enable easier starting of the mtor. For this purpose a bleeder valve is opened by the snap action mechanism when the latter opens its switch.

The invention is fully disclosed by way of example in the following description and in the ac companying drawings in which:

Figure 1 is a longitudinal section of the device.

Figure 2 is a section in the line 2-2 of Figure 1. Figure 3 is a longitudinal section of a modification;

use of like characters which are employed to v designate corresponding parts throughout.

The 'pumpingapparatus is built in a housing I standing on feet :2. The housing is formed with :a horizontal cylinder 3 and with a parallel bore 6 shown.

A motor casing 1.5 is attached to the back of the housing I. The motor contained therein comprises a winding 6 and a rotor l havinga horizontal shaft 8 mounted in ball bearings 9 and extending into the housing I. The shaft 8 is there provided with a driving pinion It geared to a pump which will now be described.

In the housing I, adjacent to the cylinder 3, is journalled a shaft ll formed with a disk l2 from which extends an eccentric pin l3. The shaft 1 i also carried a large gear [4 meshing with the pinion It). In .the cylinder 3 is mounted a double piston l5 formedwith an intermediate enlarged section [6 which has a vertical slot I'l receiving the pin 13. The cylinder 3 is in fact a pair of sections secured to opposite sides of the housing I and receiving respectively the ends of the piston l5. At each side of the enlargement IS, the piston is formed with a chamber It extending through the corresponding end of the piston where it is fitted with On inwardly closing check valve l9 and a retainer 20. The ends of the piston are fitted with packing rings that ride on the cylinder wall.

The chamber 22 containing the crosshead i5 is covered by a separate front plate 23 having an air intake opening 2 3. overlaid with filtering material 25. Air drawn into the chamber by the suction of the piston heads flows into the laterally opencavities 2|. As an end of the piston moves 'toward the chamber 22, .theair flows past the open check valve ['9 into the end of the cylinder.

On reversal of the piston, the check valve closes and the air is compressed against the adjacent end of the cylinder.

Each end of the cylinder is connected to the manifold 4 by an angular port 26. Each port is fitted with a check valve 2'! closed inwardly by a spring 28.

The fitting 29 is connected to one end. of the manifold 4 and to a line 30 leadingto. an air storage tank. The fitting is formed with a port 3| controlled by a check valve 32 which closes inwardly under the action of a spring 33. Thus, in order to charge the tank, the compressed air must overcome the spring 28. The spring 33 is lighter and merely prevents back fiow from the tank under conditions that will presently be described.

An upper chamber 35 is formed in the housing I and substantially opposite the motor casing 5.

At the chamber 35 a fitting 36 is secured to the f housing and is connected by a pipe 3! to the fitting 29 at a point between the valve 32 and the line 39. The fitting 36 contains a diaphragm 38 exposed to the pipe 31 and having a finger 39 extending into the chamber 35 for a purpose that will presently be described. The chamber 35 is open to atmosphere.

To the bottom of the chamber is secured a switch contact 59 which is insulated from the housing. Adjacent to the contact is pivotally mounted an upright lever (II, and adjacent to the lever is a shaft 42 on which is mounted a rocker arm 53. The yoke 44 is pivotally suspended from the shaft 42 and carries the complementary contact 45 and a trip finger 3-3 for a purpose that will presently be described. A pin 41 passes slidably through the bottom of the yoke and is formed at its upper end with a ball received in'a socket 49 shaped in the lower end of the rocker arm 43. A coil spring 55 surrounds the pin 41 and bears on the bottom of the yoke.

The upper end of the rocker arm is joined to the upper end of the lever dI by links 5i.

The lever M is engaged near its lower end by the finger 39 and has its upper end attached to a tension spring 52. The spring extends into a sleeve 53 in which is threaded an axial screw 5% also attached to the spring 52 for adjusting the latter.

When the air pressure in the storage tank is sufficient to overcome the spring 52, the diaphragm 5S and the finger 39 move the lever lI towards the shaft 42, thereby swinging the socket end of the rocker arm d3 toward the switch contacts. The pin ill eventually slopes downward away from the contacts, and the spring 56 effects a snap action that separates the contact 1-5 from the contact 45 and thus opens the circuit. This circuit includes a conductor 55 from the grounded battery to the motor and another conductor 5'3 from the motor to the contact it. When the tank pressure falls to a point where it no longer overcomes the spring 52, the switch contacts are again closed to operate the motor which drives the compressor.

Opposite the finger 46, a fitting 5? is mounted in the housing I and is normally closed inwardly by a check valve 58 backed by a spring 59 and having a stem 6i] extending into the path of the finger G5. The manifold i communicates with the fitting 5'I, behind the valve 58, through a port BI.

When the switch 28, 45 opens as above described, the trip finger ll; opens the valve 58 and the port ti. The port BI, however, is closed by the valve 32 under the tank pressure. The pressure in the manifold 5 is reduced to atmospheric through the chamber 35. The pump and motor re-start against a reduced load, and the motor thereby given time to develop speed.

In the modification shown in Figures 3 and i the housing I is likewise formed with a cylinder II and a parallel manifold I2. The ends of the cylinder contain pistons I3 joined by pivoted connecting rods 74 to a crank I journalled in a chamber I6 between the ends of the cylinders.

Over the top wall '11 of the chamber IE is another chamber I8 communicating with the manifold I2 through a port I9. A diaphragm 89 is clamped against the top TI by a ring BI and is exposed laterally to the port I9.

To the back of the housing In is fastened a motor casing 82 containing a motor 83 as previously described. The shaft 84 of the motor car- 'ries a pinion 85 meshing with a gear 85 on the shaft 81 of the crank I5.

Each end of the cylinder H has an intake port 38 covered by a check valve 89 closing outwardly by a spring 90. Each port 88 is also covered by a filter 9|. Each end of the cylinder also has an outlet port 92 fitted with a check valve 93 which closes inwardly by a spring 94. Behind the head of the check valve, each port 92 communicates with the manifold 12 through a port 95.

To the ring BI is pivotally attached one end of an arm 96 carrying a button 91 which bears upon the diaphragm 89. A pin 98 threaded in the top of the chamber passes loosely through the other end of the arm 96 and is surrounded by a coil spring 98 bearing upon this end. The pressure of the spring 99 is regulated by screwing the pin and determines the air pressure necessary to lift the diaphragm and the arm 95.

A shaft IQE] is mounted in the walls of the chamber 18 near the top thereon and carries a rocker arm 43' similar to the member 63. One end of the rocker arm 43' is joined to the free end of the arm 95 by links IilI. On the shaft Illil is pivotally mounted a yoke M. carrying a snap action mechanism similar to that previously described and designated in part at the numeral 47. V

A conductor I62 from the motor is brought into the chamber 18 through an insulated post I03 and is fastened to an insulated fixed contact I94. The yoke 44 lies in a nearly horizontal position and carries the complementary contact I95 which is grounded through the housing The top wall of the chamber I8 carries a differential adjustment screw I66 engageable by the yoke 46 on its upward movement. This screw regulates the switch-closing resistance of the spring in the snap action mechanism and hence the pressure at which the spring 99 will close-the switch. For example, the spring 99 may permit the switch to open at 90 pounds but will close the switch at a desired lower pressure.

An oil sump I9! is formed at the base of the housing 10 adjacent to the gear and communicates with the housing through a restricted splash-proof slot IE8. The oil is thrown by the gears and enters the chamber T6 through an upper channel I59, returning to the sump through a lower port iIEi. Baiiles III are formed on the bottom of the chamber It to reduce swashing.

In the wiring diagram, the compressed air line 35 is shown connected to the storage tank H5. The tank is connected to the horns I It through a pipe I I1 controlled by an electromagnetic valve I I8 operated by a button I I 9.

The live conductor 55' leading to the electric motor is not connected directly to the battery but to the output side of an electromagnetic relay I26. The diagram also shows the conventional generator I2I, battery I22 :andvoltage regulator I23 carried on the vehicle.

The terminals of the generator are connected by conductors I 24 and I25 respectively to the armature post I26 and field post 'I 21 of the voltage regulator. Battery posts I28 and I29 on the regulator are connected by conductors ISQ and I3I respectively to the positive and negative terminals I32 and "I33 of the battery. The conductor I24 is grounded through the generator. The tennin'al I33 is connected by 'a wire I34 to a terminal I35 of the coil of valve -I I 8, the other terminal I36 being grounded through the horn button I I9 by a conductor I31.

The relay I20 is energized and closed only by current from the generator, whereupon the conductor 55' receives current from the grounded battery. Since the generator is always turning I over when the engine is running, whether the battery is taken current ornot, the electric motor will operate the compressor while. the engine and generator are running and not otherwise. When the engine is not running, the horns can be blow until the storage tank is exhausted, butthe electric motor will not start and will not drain the battery. Another advantage of this system is that the horns are operated on 6 /2 to 7 /2 volts and 1 8 to 40 amperes available from the generator as compared with 6 volts and a lower amperage from the battery alone.

With reference to the relay in detail, it includes an actuating element or coil I40 grounded at I40, a fixed contact I41 connected to the conductor 55',

and a movable contact I42 joined by a conductor I43 to the battery post I20. The coil I40 is connected by a conductor I44 to the post I 26 which, as previously shown, is connected to the generator by the conductor I24. A spring I45 normally separates the contact I42 from the contact I4I. Regardless of the condition of the voltage regulator, the coil I40 is energized to make current available to the electric motor through the con- .taets I-4I, I42.

The grounded generator I2I, the engine, charges the grounded battery I22 through conductor I25, voltage regulator I23, conductor I and ground. The running generwhen driven by ator energizes the relay coil I40 through conduc- 6 tion has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention as indicated by the appended claims.

What I claim is:

l. A horn blowing apparatus for motor vehicles comprising, in combination with a generator adapted to be driven by the engine of a vehicle and an air horn for mounting on the vehicle, a compressor connected to said horn to furnish compressed air for blowing the horn, means for controlling the 'flow of compressed air to said horn, an electric motor for driving said compressor, an electric circuit connected to deliver current to said motor, a normally open relay connected into said circuit, said relay having circuit-closing coil electrically connected to the current output side of said generator, whereby said motor is operated only when said engine is running.

2. A horn blowing apparatus for motor vehicles comprising, in combination with a generator adapted to be driven by the engine of a vehicle,

a battery and an airhorn for mounting on the vehicle, a compressor connected to said horn to provide compressed air for blowing said horn, means for controlling the flow of compressed air to said horn, an electric motor for driving said compressor, a normally open relay having con "tac-ts connected respectively to said motor and battery, said relay having a circuit-closing coil electrically connected tothe current output side of said generator, whereby said motor is operated only when said engine is running.

FRANK M. STELLA.

REFERENCES CITED The following references are of record in the file of this patentz UNITED STATES PATENTS Number Name Date 2,240,595 White May 6, 1941 2,336,762 White Dec. 14, 1943 2,337,788 White Dec. 28, 1943 2,345,797 Corson Apr. 4, 1944 2,389,348 Dustin Nov. 20, 1945 FOREIGN PATENTS Number Country Date 462,205 France Nov. 17, 1913 

